Looks like the answer is B
But I am not sure, could be A, I know planets don't shrink when they are cold and unless the asteroid has mercury or mercury is on the planet already and the asteroid pierces it, it is not C.
An explosion occurs when the timescale for the energy release by some process is much shorter than the timescale on which a system can adjust to damp the energy release process. In the present day Sun, nuclear fusion is a very slow process: on average it takes many billion years for a proton to fuse with another. This timescale is quite temperature dependent, so you might have thought the centre of the Sun might heat up quickly, leading to a runaway "explosion". However, an increase in temperature leads to an increase in pressure that would expand the Sun, reducing the core density and temperature and decreasing the rate of nuclear fusion again. The timescale for the Sun to react in this way is just millions of years, so this acts like a thermostat that keeps the reactions under control.
The desert regions in China that are largely uninhabited are the Iner Mongolia region on the north of the country, and the Xinjiang region on the west of the country.
Saudi Arabia is a country that in most part is uninhibited and people are concentrated in the cities which are surrounded by desert and some partially from sea. The most uninhabited regions are Northern Borders, Jawf, Bahah and Najran.
The blank is surface or surface of land
